1. Field of Invention
The invention applies to sewing aids. More specifically the invention applies to devices for setting corded piping a desired spacing.
2. Prior Art
Corded piping historically is made when a strip of fabric is cut wide to cover the filler cord (or cords) and extending long enough to allow the seam allowance and trim waste. The fabric is then folded in half by the longest dimension and the filler cord is inserted in the fold. It is then sewn by the machine, usually immediately adjacent to the cord. Trimming or grading the seam to the seam width desired is accomplished by one or two prior art methods typically.
After making the corded piping, one has to measure and mark the seam allowance by using scissors to cut along the marked line cutting off the excess fabric. This is the most accurate prior art way to make corded bias piping.
Another method is to cut the fabric twice the width of the finished seam allowance plus the diameter of the filler cord used to make the piping. When sewing with this method, it is necessary to be very careful to make sure the cut edges of the fabric are lined exactly and that one knows exactly the diameter of the filler cord. The method can only be used when making piping with fabric cut on the straight of the grain. This is not an accurate method to use when making bias corded piping because the fabric stretches, becoming narrower after it is assembled when sewing in the cord and thereby losing the accuracy of the seam allowance.